THE ADVISORS’ INNER CIRCLE FUND III Rayliant Quantamental China Equity ETF (the “Fund”) Supplement, dated January 21, 2021, to the Fund’s Prospectus and Statement of Additional Information (the “SAI”), each dated December 30, 2020 This supplement provides new and additional information beyond that contained in the Prospectus and SAI and should be read in conjunction with the Prospectus and SAI. Effective immediately, all references to the Fund’s address are changed to the following: Rayliant Quantamental China Equity ETF c/o SEI Investments Distribution Co. One Freedom Valley Drive Oaks, Pennsylvania 19456 Please retain this supplement for future reference. RAY-SK-001-0100 STATEMENT OF ADDITIONAL INFORMATION RAYLIANT QUANTAMENTAL CHINA EQUITY ETF TICKER SYMBOL: RAYC Principal Listing Exchange: NYSE Arca, Inc. a series of THE ADVISORS’ INNER CIRCLE FUND III December 30, 2020 Investment Adviser: RAYLIANT INVESTMENT RESEARCH doing business as RAYLIANT ASSET MANAGEMENT This Statement of Additional Information (“SAI”) is not a prospectus. This SAI is intended to provide additional information regarding the activities and operations of The Advisors’ Inner Circle Fund III (the “Trust”) and the Rayliant Quantamental China Equity ETF (the “Fund”). This SAI is incorporated by reference into and should be read in conjunction with the Fund’s prospectus dated December 30, 2020, as it may be amended from time to time (the “Prospectus”). Capitalized terms not defined herein are defined in the Prospectus. Shareholders may obtain copies of the Prospectus or the Fund’s annual or semi-annual report, when available, free of charge by writing to the Fund at Rayliant Quantamental China Equity ETF, P.O. Box 219009, Kansas City, MO 64121-9009 (Express Mail Address: Rayliant Quantamental China Equity ETF, c/o DST Systems, Inc., 430 West 7th Street, Kansas City, MO 64105) or calling the Fund at 866-898-1688. TABLE OF CONTENTS THE TRUST S-1 DESCRIPTION OF PERMITTED INVESTMENTS S-2 INVESTMENT LIMITATIONS S-40 EXCHANGE LISTING AND TRADING S-42 THE ADVISER S-43 THE PORTFOLIO MANAGERS S-44 THE ADMINISTRATOR S-45 THE DISTRIBUTOR S-45 PAYMENTS TO FINANCIAL INTERMEDIARIES S-46 THE TRANSFER AGENT S-48 THE CUSTODIAN S-48 INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM S-48 LEGAL COUNSEL S-48 SECURITIES LENDING S-48 TRUSTEES AND OFFICERS OF THE TRUST S-48 BOOK ENTRY ONLY SYSTEM S-58 PURCHASE AND REDEMPTION OF SHARES IN CREATION UNITS S-59 DETERMINATION OF NET ASSET VALUE S-69 DIVIDENDS AND DISTRIBUTIONS S-70 FEDERAL INCOME TAXES S-71 FUND TRANSACTIONS S-82 PORTFOLIO HOLDINGS DISCLOSURE POLICIES AND PROCEDURES S-84 DESCRIPTION OF SHARES S-85 LIMITATION OF TRUSTEES’ LIABILITY S-85 PROXY VOTING S-85 CODES OF ETHICS S-85 PRINCIPAL SHAREHOLDERS AND CONTROL PERSONS S-85 APPENDIX A – DESCRIPTION OF RATINGS A-1 APPENDIX B – PROXY VOTING POLICIES AND PROCEDURES B-1 December 30, 2020 RAY-SX-002-0100 THE TRUST General. The Fund is a separate series of the Trust. The Trust is an open-end investment management company established under Delaware law as a Delaware statutory trust under a Declaration of Trust dated December 4, 2013 (the “Declaration of Trust”). The Declaration of Trust permits the Trust to offer separate series (“funds”) of shares of beneficial interest (“shares”). The Trust reserves the right to create and issue shares of additional funds. Each fund is a separate mutual fund or exchange traded fund (“ETF”), and each share of each fund represents an equal proportionate interest in that fund. All consideration received by the Trust for shares of any fund, and all assets of such fund, belong solely to that fund and would be subject to any liabilities related thereto. Each fund of the Trust pays its (i) operating expenses, including fees of its service providers, expenses of preparing prospectuses, proxy solicitation material and reports to shareholders, costs of custodial services and registering its shares under federal and state securities laws, pricing and insurance expenses, brokerage costs, interest charges, taxes and organization expenses and (ii) pro rata share of the fund’s other expenses, including audit and legal expenses. Expenses attributable to a specific fund shall be payable solely out of the assets of that fund. Expenses not attributable to a specific fund are allocated across all of the funds on the basis of relative net assets. The other funds of the Trust are described in one or more separate statements of additional information. Exchange Traded Fund Structure. The Fund operates as an ETF. Rayliant Investment Research, doing business as Rayliant Asset Management (the “Adviser” or “Rayliant”), serves as the investment adviser to the Fund. The investment objective of the Fund is to seek long-term capital appreciation. As an ETF, the Fund offers and issues shares at their net asset value (“NAV”) only in aggregations of a specified number of shares (each, a “Creation Unit”). The Fund generally offers and issues shares in exchange for a basket of securities (“Deposit Securities”) together with the deposit of a specified cash payment (“Cash Component”). The Trust reserves the right to permit or require the substitution of a “cash in lieu” amount (“Deposit Cash”) to be added to the Cash Component to replace any Deposit Security. The Fund’s shares are listed on NYSE Arca, Inc. (the “Exchange”) and trade on the Exchange at market prices. These prices may differ from the Fund’s NAV per share. The Fund’s shares are redeemable only in Creation Unit aggregations, and generally in exchange for portfolio securities and a specified cash payment. Voting Rights. Each shareholder of record is entitled to one vote for each share held on the record date for the meeting. The Fund will vote separately on matters relating solely to it. As a Delaware statutory trust, the Trust is not required, and does not intend, to hold annual meetings of shareholders. Approval of shareholders will be sought, however, for certain changes in the operation of the Trust and for the election of members of the Board of Trustees of the Trust (each, a “Trustee” and collectively, the “Trustees” or the “Board”) under certain circumstances. Under the Declaration of Trust, the Trustees have the power to liquidate the Fund without shareholder approval. While the Trustees have no present intention of exercising this power, they may do so if the Fund fails to reach a viable size within a reasonable amount of time or for such other reasons as may be determined by the Board. In addition, a Trustee may be removed by the remaining Trustees or by shareholders at a special meeting called upon written request of shareholders owning at least 10% of the outstanding shares of the Trust. In the event that such a meeting is requested, the Trust will provide appropriate assistance and information to the shareholders requesting the meeting. Any series of the Trust may reorganize or merge with one or more other series of the Trust or of another investment company. Any such reorganization or merger shall be pursuant to the terms and conditions specified in an agreement and plan of reorganization authorized and approved by the Trustees and entered into by the relevant series in connection therewith. In addition, such reorganization or merger may be authorized by vote of a majority of the Trustees then in office and, to the extent permitted by applicable law and the Declaration of Trust, without the approval of shareholders of any series. S-1 Non-Diversification. The Fund is non-diversified, as that term is defined under the Investment Company Act of 1940, as amended (the “1940 Act”), which means that it may invest a greater percentage of its total assets in the securities of fewer issuers than a “diversified” fund, as that term is defined under the 1940 Act, which increases the risk that a change in the value of any one investment held by the Fund could affect the overall value of the Fund more than it would affect that of a “diversified” fund holding a greater number of investments. Accordingly, the value of the shares of the Fund may be more susceptible to any single economic, political or regulatory occurrence than the shares of a “diversified” fund would be. The Fund intends to satisfy the diversification requirements necessary to qualify as a regulated investment company ("RIC") under the Internal Revenue Code of 1986, as amended (the “Code”). For more information, see “Taxes” below. DESCRIPTION OF PERMITTED INVESTMENTS The Fund’s investment objective and principal investment strategies are described in the Prospectus. The following information supplements, and should be read in conjunction with, the Prospectus. The following are descriptions of the permitted investments and investment practices of the Fund and the associated risk factors. The Fund may invest in any of the following instruments or engage in any of the following investment practices unless such investment or activity is inconsistent with or is not permitted by the Fund’s stated investment policies, including those stated below. American Depositary Receipts (“ADRs”) ADRs, as well as other “hybrid” forms of ADRs, including European Depositary Receipts (“EDRs”) and Global Depositary Receipts (“GDRs”), are certificates evidencing ownership of shares of a foreign issuer. Depositary receipts are securities that evidence ownership interests in a security or a pool of securities that have been deposited with a “depository” and may be sponsored or unsponsored. These certificates are issued by depository banks and generally trade on an established market in the United States or elsewhere. The underlying shares are held in trust by a custodian bank or similar financial institution in the issuer’s home country. The depository bank may not have physical custody of the underlying securities at all times and may charge fees for various services, including forwarding dividends and interest and corporate actions.